Abstract: Breaking waves on the tropopause are viewed as potential vorticity (PV) streamers on middle-world isentropic levels. A Northern Hemisphere winter climatology of the streamers? spatial distribution and meridional orientation ...

Abstract: Jet streams located on the dynamical tropopause are accompanied by coaligned bands of enhanced potential vorticity (PV) gradients, and these bands can serve as space?time evolving waveguides for synoptic and larger-scale ...

Abstract: A dynamically based climatology is derived for Northern Hemisphere atmospheric blocking events. Blocks are viewed as large amplitude, long-lasting, and negative potential vorticity (PV) anomalies located beneath the dynamical ...

Abstract: The applicability of three different cyclone detection and tracking schemes is investigated with reanalysis datasets. First, cyclone climatologies and cyclone characteristics of the 40-yr ECMWF Re-Analysis (ERA-40) are ...

Abstract: Recent developments in numerical modeling and computer technology will soon allow for limited-areaproduction-type numerical weather prediction at a resolution of 1-2 km. This advance opens exciting prospects for the ...